Friction brake



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N O s P .M O H T 5 l FRICTION BRAKE Filed May 1, 1926 Patented Aug. 13, 1929;

UNITED STATES PATE'NTYOFFICE'.

JAMES s. THOMPSON, or New YORK, n. nssisnoza TO AMERICAN BRAKE MA- TERIALS conronn'rron, or new YORK, n. Y.,'-A CORPORATION or new YORK.

FRICTION- BRAKE.

Application filed May 1,

This invention relates to friction brakes and while it i'sparticularly adapted fqr ex pending brakes arranged -.to ,-fmake-fr1ct1on V contactfwith a drum; whichjis'a form ofbrake commonly e ployed in automotivevehicles, it is'also useful in many other .installations as willbe-apparent to those skilled.

in the art.

' struction and embodying a removable fries tion shoe and simple means for securingsa'id shoe inoperatiiie position.

provide an internal expanding brake comprising a pivoted head and a 'detachablefriction shoe with means. for securing the f "ctio'n-shoe in fixedpos'ition on the head.

And a further object of the inventionis to provideclamps for engaging a friction shoe. with a brake head and radially disposed bolts for securing said clampsto the head;

In the accompanying drawings fillustrat ing a selected embodiment-of theinvention which I have found satisfactory in commercial test,

Fig. 1 is a sectional elevation of parts of" .8. brake assembly showing my invention applied thereto. I

Fig. 2 is an enlarged plan view, partly in section, showing a part of the shoe broken away to disclose the seat onthe brake head. Fig-3 is a sectional. view of the parts shown in Fig. 2. d Referring to the drawing 4 is the brake drum, 5, 5 are the brake heads which are pivotally mounted on the studs 6, 6 and are adapted to be operated by the cam 7 and into and out of operative contact with the drum. The construction of the drum, the manner of mounting the brake heads and the mechanism for operating the brake heads are not involved in this invention, and the invention can be embodied in brake assemblies of different kinds. v

The head comprises a comparatively, narrow arm substantially shaped in cross section, and enlarged laterally at 10 to provide shoulders 11 which are spacedapart lengthwise of thearm to engage the back of the shoe at the ends thereof. The shoe is free from engagement with the head except at the shoulders and this provides for ventilation at the back of the shoe. For some pup the spring 8 to move the friction shoes 9, 9

1926. Serial No. 105,897.

poses it may be desirable that the back of the shoe should contact with the head. 1 throughout its area in which case the shoul ders 11 would continue in effect to form a single continuous shoulde'r'or seat extending from end to'end of the shoe. a

The enlarged portions 10 of the arm are extend throughout said enlarged portions as shown in Fig. 2. ,Clamps 13 are shaped-to seat in said'slotsand they are provided with projections l4e'which engage recesses 15 in" I I the shoe. The projections preferably make a A further object of the inventidn is. to,

"comparatively snug fit in the recesses and located midway between'the ends of the clamp and sides of the shoe respectively.

- x The side walls'ofthe slots and the sides of the clamps are parallel and the parts pro-' portioned so that the clamps will fit snugly \in the slots; These clamps are secured to the head by bolts 16 which are disposed radially through the clamps and the head and are held by nuts 17.

v I have found this construction and arrangement of parts desirable for embodying my invention in an internal automotive brake assembly. The shoes can be easily installed upon the heads and replaced as required; 'Tprefer to locate the shoes approximately midway between the ends of the heads so that the two shoes will be substantially diametrically opposed with the drum.- The clamps are engaged with the head, on parallel lines and the bolts are engaged with the clamps and the head on radial lines; and the bolts are of greater length than the maximum operative distance between the head andflthe rim of the drum. If the nuts shouldwork loose or if they should not be applied to the bolts the latter will hold the clamps in-place in their slot seats in the head and the ttlamps will hold the shoe in: its proper position on the head at all times,.hecause'th e bolts cannot be re- 10o provided with transverse slots 12 which may l v r The object ofthe invention is to provide 10.,a n internal expanding brake of novel conice 2. bolt from which the nut has been removedwill not fall out by gravity because its head Will engage the rim of the drum and hold the bolt. I propose, of course, to provide the bolts with nuts, and also with lock nuts if it may be found desirable, but the construction is such that if throughcarelessness the nuts are not applied to the bolts or if the nuts work off the bolts no harm can I result because the shoe will be held in proper position on its seat.

Shoulders 18 extend throughout the length of the clamps to provide end stops at the ends of the shoe throughout the width of the. shoe. The projections 14 are of less length. than the length of the clamps but they are suflicient to make operative engagement with the shoe for preventing outward movement of the shoe away from its seat and also forpreventing sidewise movement of the shoe. There is not much tendency for the shoe to move outward or sidewis'e and therefore it is found that the projections are shfiieient fort-he purpose. There is a tendency for the shoe to move lengthwise under application of the brake and for .that' reason substantial end stops are provided by the shoulders on the clamps.

The shoe shown in the drawing is provided. with. a metal back 19 and the metal is folded upon itself to form a doublethickness at 20 in the bottom of the recesses '15 to be engaged by the projections 14.

I am aware that changes in the form, construction and arrangement of parts of my invention will be made to adapt it for dif-- ferent installations and to meet different conditions and. I reserve the right to make all such changes as fall within. the scope of the following claims.

ICl8,imZ -1.In' a. friction. brake, a brake head having a shoe seat thereon and transverse slots with plane parallel side walls at the ends of said seat, clamps having parallel side walls and adapted to be seated in said slots, a friction shoe, said clamps comprising circumferentially-disposed projecting parts en- ,gagiug the ends ofthe shoe to hold the shoe inplace on the seat. and angularly disposed means forsecuring the clamps on the head. 7 2. In a friction brake, a brake head having a shoe seat thereon and transverse slots with plane parallel side walls at the ends of said seat. a friction shoe, clamps with parallel side walls seated in said slots and comprising circumferentially projecting parts engaging the ends of the shoe to hold the shoe in place on the seat, and fastening means disposed radially through the clamps and head at the slots for securing the clamps to the head.

3. In a friction brake, a brake head having a shoe seat thereon and transverse slots with parallel side walls at the ends of said seat-,a friction shoe having recesses in its ends, clamps having parallel side walls and adapted to be seated in said slots and having projections toengage the recesses in the shoe and shoulders to engage the ends of the shoe to hold the shoe in pfce on the seat, and bolts passing radially through the clamps and the head for securing the clamps to the head.

4. An internal friction brake comprising a rim, a brake head arranged within the rim.

- a brake shoe seated on the head to engage 

